Skip to main content
Earth, Planets and Space
Download PDF

Volume 56 Supplement 12

Special Issue: Slip and Flow Processes in and below the Seismogenic Region (2)

  • Article
  • Published:

Mid-crustal electrical conductors and their correlations to seismicity and deformation at Itoigawa-Shizuoka Tectonic Line, Central Japan

Earth, Planets and Space volume 56, pages 1285–1291 (2004)Cite this article

Abstract

An active fault segment at the northern Itoigawa-Shizuoka tectonic line (ISTL), Central Japan, which will potentially cause M8-class intraplate earthquake, was imaged by wide-band magnetotellurics. Three parallel profiles across ISTL revealed along-strike variation of the resistivity structure. Three resistivity models commonly showed the thickening conductors in the upper crust to east of ISTL which imply the heavily folded Miocene sediments with maximum thickness of several kilometers. Thus the upper crustal structure seems two-dimensional throughout the segment. We found mid-crustal conductors, top of which correlate well with the cutoff depth of seismicity. The seismicity clusters mainly in the resistive crust that is underlain by the mid-crustal conductors. This implies the local distribution of fluids below the brittle-ductile boundary and suggests that the fluid migration into resistive zone is triggering earthquakes. However, the distribution of these mid-crustal conductors is not consistent with the strike of ISTL, but rather it is better correlated with the negative dilatation anomaly inferred from GPS. This suggests the weakening of the crust by the existence of fluids.

References

  • Cox, S., Fluid flow in mid- to deep crustal shear systems: Experimental constraints, observations on exhumed high fluid flux shear system, and implications for seismogenic processes, Earth Planets Space, 54, 1121–1125, 2002.

    Article  Google Scholar 

  • Fujimoto, K., T. Ohtani, N. Shigematsu, Y. Miyashita, T. Tomita, H. Tanaka, K. Omura, and Y. Kobayashi, Water-rock interaction observed in the brittle-plastic transition zone, Earth Planets Space, 54, 1127–1132, 2002.

    Article  Google Scholar 

  • Gratier, J-P, P. Favreau, F. Renard, and E. Pili, Fluid pressure evolution during the earthquake cycle controlled by fluid flow and pressure solution crack sealing, Earth Planets Space, 54, 11, 1139–1146, 2002.

    Article  Google Scholar 

  • Hobbs, B. E., H. Tanaka, and Y. Iio,, Earth Planets Space, 54, 1195–1205, 2002.

    Article  Google Scholar 

  • Honkura, Y., A. M. IÅŸikara, N. Oshiman, A. Ito, B. Üçer, Åž. BariÅŸ, M. Tunçer, M. Matsushima, R. PektaÅŸ, C. Çelik, B. Tank, F. Takahashi, M. Nakanishi, R. Yoshimura, Y. Ikeda, and T. Komut, Preliminary results of multidisciplinary observations before, during and after the Kocaeli (Izmit) earthquake in the western part of the North Anatolian Fault Zone, Earth Planets Space, 52, 293–298, 2000.

    Article  Google Scholar 

  • Iio, Y. and Y. Kobayashi, A physical understanding of large intraplate earthquakes, Earth Planets Space, 54, 1001–1004, 2002.

    Article  Google Scholar 

  • Ikeda, Y. and N. Yonekura, Determination of late Quaternary rates of net slip on two major fault zones in Central Japan, Bull. Dept. Geogr. Univ. Tokyo, 18, 49–63, 1986.

    Google Scholar 

  • Iwamori, H., Transportation of H2O and melting in subduction zones, Earth Planet. Sci. Lett., 160(1–2), 65–80, 1998.

    Article  Google Scholar 

  • Jones, A. G., Electrical conductivity of the lower continental crust, in Continental Lower Crust, edited by D. M. Fountain, R. J. Arculus, and R. W. Kay, Elsevier, Chapter 3, pp. 81–143, 1992.

    Google Scholar 

  • Kasaya, T., N. Oshiman, N. Sumitomo, M. Uyeshima, Y. Iio, and D. Uehara, Resistivity structure around the hypocentral area of the 1984 Western Nagano Prefecture earthquake in central Japan, Earth Planets Space, 54, 107–118, 2002.

    Article  Google Scholar 

  • Kobayashi, Y., Initiation of plate subduction, Earth-Monthly, 5, 510–514, 1983 (in Japanese).

    Google Scholar 

  • Lemonnier, C., G. Marquis, F. Perrier, J-P. Avouac, G. Chitrakar, B. Kafle, S. Sapkota, U. Gautam, G. Tiwari, and M. Bano, Electrical structure of the Himalaya of Central Nepal: High conductivity around the mid-crustal ramp along the MHT, Geophys. Res. Lett., 26, 3261–3264, 1999.

    Article  Google Scholar 

  • Matsubara, M., N. Hirata, S. Sakai, and I. Kawasaki, A low velocity zone beneath the Hida Mountains derived from dense array observation and tomographic method, Earth Planets Space, 52, 143–154, 2000.

    Article  Google Scholar 

  • Miller, S. A., Inferring fault strength from earthquake rupture properties and the tectonic implications of high pore pressure faulting, Earth Planets Space, 54, 1173–1179, 2002.

    Article  Google Scholar 

  • Mitsuhata, Y., Y. Ogawa, M. Mishina, T. Kono, T. Yokokura and T. Uchida, Electromagnetic heterogeneity of the seismogenic region of 1962 M6.5 Northern Miyagi Earthquake, northeastern Japan, Geophysical Research Letters, 28, 4371–4374, 2001.

    Article  Google Scholar 

  • Nakamura, K., Possible nascent trench along the eastern Japan Sea as the convergent boundary between Eurasian and North American plates, Bull. Earthq. Res. Inst. Univ. Tokyo, 58, 711–722, 1983 (in Japanese).

    Google Scholar 

  • Ogawa, Y., On two-dimensional modeling of magnetotelluric field data, Surveys in Geophysics, 23(2–3), 251–273, 2002.

    Article  Google Scholar 

  • Ogawa, Y. and Y. Honkura, An audiomagnetotelluric view of the Atera fault, J. Geomag. Geoelectr., 49, 1065–1071, 1997.

    Article  Google Scholar 

  • Ogawa, Y. and T. Uchida, A two-dimensional magnetotelluric inversion assuming Gaussian static shift, Geophys. J. Int., 126, 69–76, 1996.

    Article  Google Scholar 

  • Ogawa, Y., M. Mishina, T. Goto, H. Satoh, N. Oshiman, T. Kasaya, Y. Takahashi, T. Nisitani, S. Sakanaka, M. Uyeshima, Y. Takahashi, Y. Honkura, and M. Matsushima, Magnetotelluric imaging of fluids in intraplate earthquakes zones, NE Japan back arc, Geophysical Research Letters, 28, 3741–3744, 2001.

    Article  Google Scholar 

  • Ogawa, Y., S. Takakura, and Y. Honkura, Resistivity structure across Itoigawa-Shizuoka tectonic line and its implications for concentrated deformation, Earth Planets Space, 54, 1115–1120, 2002.

    Article  Google Scholar 

  • Okumura, K., K. Shimokawa, H. Yamazaki, and E. Tsukuda, Recent surface faulting along the middle section of Itoigawa-Shizuoka tectonic line-3√enching survey of the Gofukuji fault near Matsumoto, central Japan, Zisin, 46, 425–438, 1994 (in Japanese).

    Google Scholar 

  • Ritter, O., T. Ryberg, U. Weckmann, A. Hoffmann-Rothe, A. Abueladas, Z. Garfunkel, and DESERT-group, Geophysical images of the Dead Sea Transform in Jordan reveal an impermeable barrier for fluid flow, Geophysical Research Letters, 30, 14, 1741–1744, 10.1029/2003GL017541, 2003.

    Article  Google Scholar 

  • Sagiya, T., T. Nishimura, Y. Iio, and T. Tada, Crustal deformation around the northern and central Itoigawa-Shizuoka Tectonic Line, Earth Planets Space, 54, 1059–1063, 2002.

    Article  Google Scholar 

  • Sagiya, T., T. Nishimura, and Y. Iio, Heterogeneous crustal deformation along the central-northern Itoigawa-Shizuoka Tectonic Line Fault system, Central Japan, Earth Planets Space, 56, this issue, 1249–1254, 2004.

    Article  Google Scholar 

  • Sato, H. and Y. Ikeda, Crustal structure of NE Japan and extension tectonics, Earth Monthly, special volume, 27, 135–141, 1999. (in Japanese)

    Google Scholar 

  • Sato, H., T. Iwasaki, Y. Ikeda, T. Takeda, N. Matsuta, T. Imai, E. Kurashimo, N. Hirata, S. Sakai, D. Elouai, T. Kawanaka, S. Kawasaki, S. Abe, T. Kozawa, T. Ikawa, Y. Arai, and N. Kato, Seismological and geological characterization of the crust in the southern part of northern Fossa Magna, central Japan, Earth Planets Space, 56, this issue, 1255–1261, 2004.

    Google Scholar 

  • Sibson, R. H., F. Roberts, and K. H. Paulson, High-angle reverse faults, fluid-pressure cycling and mesothermal gold deposits, Geology, 16, 551–555, 1988.

    Article  Google Scholar 

  • Tanaka, A. and Y. Ishikawa, Temperature distribution and focal depth in the crust of the northeastern Japan, Earth Planets Space, 54, 1109–1113, 2002.

    Article  Google Scholar 

  • Tank, S. B., Y. Honkura, Y. Ogawa, N. Oshiman, M. K. Tunçer, M. Matsushima, C. Çelik, E. Tolak, and A. M. IÅŸikara, Resistivity structure in the western part of the fault rupture zone associated with the 1999 Ä°zmit earthquake and its seismogenic implication, Earth Planets Space, 55, 437–442, 2003.

    Article  Google Scholar 

  • Tank, S. B., Y. Honkura, Y. Ogawa, M. Matsushima, N. Oshiman, M. K. Tuncer, C. Celik, E. Tolak, and A. M. Isikara, Magnetotelluric imaging of the fault rupture area of the 1999 Izmit (Turkey) earthquake, Phys. Earth Planet Interior, 2004 (in press).

    Google Scholar 

  • Unsworth, M., G. Egbert, and J. Booker, High-resolution electromagnetic imaging of the San Andreas fault in Central California, J. Geophys. Res., 104, 1131–1150, 1999.

    Article  Google Scholar 

  • Wannamaker, P. E., S. H. Ward, and G. W. Hohmann, Magnetotelluric responses of three-dimensional bodies in layered earth, Geophysics, 49, 1517–1533, 1984.

    Article  Google Scholar 

  • Wannamaker, P. E., G. R. Jiracek, J. A. Stodt, T. G. Caldwell, V. M. Gonzalez, J. D. McKnight, and A. D. Porter, Fluid generation and pathways beneath an active compressional orogen, the New Zealand Southern Alps, inferred from magnetotelluric data, J. Geophys. Res., 10.1029/2001JB000186, 2002.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Volcanic Fluid Research Center, Tokyo Institute of Technology, Tokyo, Japan

    Yasuo Ogawa

  2. Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Tokyo, Japan

    Yoshimori Honkura

Authors
  1. Yasuo Ogawa
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yoshimori Honkura
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Yasuo Ogawa.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ogawa, Y., Honkura, Y. Mid-crustal electrical conductors and their correlations to seismicity and deformation at Itoigawa-Shizuoka Tectonic Line, Central Japan. Earth Planet Sp 56, 1285–1291 (2004). https://doi.org/10.1186/BF03353352

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1186/BF03353352

Key words